Cylinder



Nav. 24,1925. 1,562,555

. W. S.v HARLEY CYLINDER Filed June 5, 1919 2 Sheets-Sheet 1 Nov.24,1925. 1,562,555

W. S. HARLEY CYLINDER Filed June 5. 1919 2 Sheets-Sheet 2 vvlO PatentedNov. 24, '1.925.'

UNITED STATES. PAT-ENT o1=i=ic|i:.l

WIIILLIJALMI S. HARLEY, OF MILWAUKEE, WISCONSIN, ASSIGNOR TOHARLEY-DAVIDSON' MOTOR CO., OF MILWAUKEE, WISCONSIN, A CORPORATION OFWISCONSIN. I

CYLINDER.

Appiication inea J'un'e 5,'i919. serial No. 302,006.-

To all whom t 'mag/(concern:

Be it known that I, YVILLIAM S. HARLEY,

a citizen of the United States, residing at B'Iilwaukee, in the countyof Milwaukee and State of lVisconsin, have invented new to make acylinder of a metal of high.

thermal conductivity.

A further object is to provide a cylinder of high radiating efficiency.

A further object is to'niake a cylinder having a large active radiatingsurface.

' A further object is to make a light weight cylinder.

A further object is to minimize wear.

A further object isto reinforce the cylinder at the points where thegreatest wear comes.

A further object is to produce a coniposife cylinder in such a mannerthat when the cylinder expands a metal to metal conktact will bemaintained whereby the maximum thermal conductivity will be maintained.

A further object is to provide a rcin force for a cylinder which will besecurely anchored 'in place.

A further object is to provide a i'einforce of such configuration thatthere will be a minimum possibility of a leak along the line of contactbetween the sides of the reinforce and thc cylinder body.

A further object is to so arrange the reinforcing means that strains areproperly distributed in the cylinder body.

Embodinients of the invention are shown in the accompanying drawings.

Fig. 1 is a longitudinal sectional view of a gasoline motor cylindershowing in dotted lines the position of the .piston therein.

Fig. 2 is a transverse sectional view of the structure shown in Fig. 1,taken along the line 2-2 in Fig. 1.

Fig. 3 is a view similar to Fig. 2, showing aI modified arrangement ofreinforcing members.

Fi 4 is a detail of the reinforcing member sown in Figs. 1, 2 and 3.

Figs .5 and 6 show further forms of reinforcing members.

Fig. 1 shows a section of a cylinder coinposed of aluminum. Aluminum isused bercause of 'its high thermal conductivity'. This property 1sutilized by employing long radiating ns, thereby securing a largeeffective radiating surface. The effective use of large radiatingsurfaces is possible when a metal of high thermal conductivity is usedas the heat is readily transmitted to the extreme tips of the radiatingfins, thereby making all of the radiating surface effective in securingproper cooling ofthe cylinder.

Fig. 1 further shows a section of a cylinder having a main or bodyportion l, composed of aluminum and reinforced by a plurality of inserts2 and 3, of harder wearresisting material. These inserts vare distinctand separate from each other, a section. through the cylinder showingabout equal alternate widths of reinforces and aluminum, as may be seenfrom Fig. 2.

The lateral thrust from the piston on its 'explosion stroke is towardone side of the cylinder and on its compression stroke toward the otherside of the cylinder in a plane through the center line of the cylinderand at right angles to the crankshaft. This lateral thrust is bornesuccessively by the two reinforces or inserts 2-2 on diamctricallyopposite sides of the cylinder.

Fig. 2 shows four of these reinforces arranged at 90 degree pointsaround the inner portion of the cylinder. The pairof reinforces 3-3 areadapted to take up 'any wear coming upon the sides of the cylinder, andthe reinforces'2 are adapted to take up the wear caused by thethrust ofthe piston previously described.

F ig. 3 is a sectional view similar lo Fig. 2, showing 'a constructionof cylinder in which there are two reinforces -la corresponding to thereinforces 2-2 Figs. 1 and 2. In some cases it may be found desirable toprovide only these two reinforces as they carry the main thrust ofthepiston.

Fig. 4f is a detail of the forni of reinforce shown' in' Figs. 1, 2 and3. This reinforce comprises a main body portion 2, having outwardlyprojecting lugs or ears 5, provided on each side thereof and arranged ina staggered relation to secure proper anchoring .of the reinforce.Additional means for anchoring the reinforce are provided by means ofthe `countersunk holes 6J Fig. shows a reinforce similar to that shownin Fig. 4, except for the shape or configuration of the side ed esthereof. These side edges are formed o a plurality of scallops forming aflnted or wave-like edge 7 for the reinforce.

Fig. 6 is a further form of reinforce in which the side edges 8 arestraight.

In all of the forms of reinforcing or wear resisting members, the sideedges are bevelled so that the surrounding aluminum has a grippingaction thereon.

In making the cylinder the reinforces are properly positioned and castin the aluminum cylinder, the 'aluminum passing through the countersunkholes and around the bevelled edges and securely anchoring thereinforces in place. Subsequently the aluminum cylinder and reinforces,or inserts, are machined out to the proper cylinder bore. This providesa uniformly smooth inner surface for the composite cylinder.

In the form of reinforce shown in Figs. 4 and 5, any slight opening thatmight occur between the edges of the reinforce and the cylinder bodyproper, due to unequal expansion. would offer a tortuous path to anyleaking gases which might pass by the piston.

By having the reinforces of relatively small lateral dimensions ascompared with the inner periphery of the cylinder, such reinforces willnot tend to pull away from the cylinder body, but will move outwardlywith the cylinder body as the cylinder expands, although the reinforcesand cylinder may have different roellicients of expansion. This insuresa cylinder of high thermal. conductivity and unitary construction inwhich the strains are 'properly distributed in the cylinder body.

By forming the cylinder of a metal of high thermal conductivity and byproviding Wide radiating fins, a cylinder of high radiating efficiencyis produced.

It is to be understood that where aluminum is referred to herein, thatit is intended to include also aluminum alloys.

vposition and for dissipating heat.

2. An aluminum cylinder having wear resisting inserts cast integral withthe cylinder on opposite sides thereof to take the side thrust of thepiston due to the crank connection, there being substantiallongitudinally extending portions of the aluminum body exposed Withinthe cylinder.

l 3. An aluminum cylinder having a small number of relatively large wearresrsting longitudinally extending inserts cast integral with thecylinder on opposite sides thereof to take the side thrust of the pistondue to the angularity of the crank connection, each of said insertshaving indented edges for engagement with the aluminum body for holdingthe insert in position and for dissipating the heat.

4. An aluminum cylinder having a wear resisting insert cast integrallytherewith, said insert having conntersunk openings for engagement by thealuminum forming the wall of the casing to securely anchor t'be insertsin position.

5. An aluminum cylinder having n pair of wear resisting inserts castintegrally therewith on opposite sides thereof and extendingsubstantially the length of the cylinder to take the side thrust of thepiston due to the crank connection, each of said insertshaving irregularbeveled edges for engagement by the aluminum body to securely anchor thesame in position.

An aluminum cylinder having wear resisting inserts' cast integ1allytherewith and extending longitudinally thereof, each of said inscrishaving irregular beveled edges and conntcrsnnk openings for cngagen'ientby the aluminum forming the wall of the casing to securely anchor theinserts in position.

In witness whereof, I have hereunto subscribed my name.

WILLIAM S. HARLEY.

